Transmission lugging the engine

[tuffs93]

Guys, Just took the wife's truck to town, had been running like a top. Was waiting for her to get some food at one of the fast food places, truck idling with the a.c. on. When she came out I put it in R and it pulled the R.P.M.'s down to around 500, did not stall the engine. Put it back in park and the R.P.M. jumped to 1200 then back to idle. After you start moving in D or R it runs normally and shifts normally. On one of the posts I read , it could be a stator in the converter ??? Truck has 159K on it and has only pulled a couple of trailers in its whole life, like I said its the wife's truck. Any help would be appreciated, Thanks

 

[cerberusiam]

Either that or your FCA is acting up. In gear the idle rpms should be the same as neutral. If there is excess load in gear the ECU will up the fuel and the truck try to pull thru the brakes. If it isn't pulling thru the brakes try some additive and extra lube in the tank.

 

[rscurtis]

I don't think it's the stator, as the stator would be locked when the truck is idling in gear. Sounds to me like the converter clutch is trying to engage.

 

[sag2]

I would think if there was a load on the engine the governor would pull the RPM back up to 750. Are you sure it isn't normal and since it is hers you haven't noticed it before? Has it been flashed?

 

[cerberusiam]

Stator is uunlocked from the input shaft at an idle and basically anything under 25 mph or so. The fluid flow across the stator when the differential is high enough will no longer keep the sprag clutch locked. It goes into free wheel, this is what determines the flash stall of the TC.


When the rpms drop like that under a load it is almost always a fuel system problem. The FCA sticking at low opening demand is the most common problem.